Telephone call centers that handle calls to toll-free "800" numbers are well-known in the art. Typically, a company may have many call centers, all answering calls made to the same set of 800 numbers. Each of the company's call centers usually has an automatic call distributor (ACD) or similar equipment capable of queuing calls. ACD management information systems keep statistics on agent and call status, and can report these statistics on frequent intervals. Such capabilities are in use today for centralized reporting and display of multi-location call center status.
In such systems, the company will want to distribute the calls to its call centers in a way that will optimally meet its business goals. Those goals might include low cost of call handling, answering most calls within a given amount of time, providing customized handling for certain calls, and many others. It is also known in the prior art that certain call routing criteria and techniques support a broad range of business goals. These include "load balancing," "caller segmentation" and "geographic routing." Load balancing refers to distribution of calls so that the expected answer delay for new calls is similar across all the call centers. If other considerations do not dictate otherwise, load balancing is desirable because it provides optimum efficiency in the use of agents and facilities, and it provides the most consistent grade of service to callers. In special situations it might be desirable to unbalance the load in a particular way, but control over the distribution of call load is still desired.
If the caller's identity can be inferred from the calling number, caller-entered digits, or other information, that identity may influence the choice of destination for the call. Call routing based on such information is referred to as caller segmentation. Also, it has been found desirable for particular call centers to handle calls from particular geographic areas. The motivation may be to minimize call transport costs, to support pre-defined call center "territories", or to take advantage of agents specifically trained to handle calls from given locations. Such techniques are known as geographic routing.
The interexchange carriers who provide 800 service today generally support some form of "routing plan" to help achieve load balancing, caller segmentation and geographic routing. Typically these routing plans allow 800 call routing based on time of day, day of week, the caller's area code, caller-entered digits, and fixed percentage allocations. Predominately, however, the routing plans supported by the carriers are static in the sense that they do not automatically react to unexpected variations in incoming call volume or distribution, nor to actual call delays being experienced at each destination. Reaction to changing conditions is done via manual modification of the plan, on a time scale of minutes or hours.
Recent service offerings from some interexchange carriers offer some degree of automatic reaction to changing conditions. One such offering, called "alternate termination sequence" or "ATS" (from AT&T), allows customers to establish maximum numbers of calls to be queued for each destination, with a pre-defined alternative when a primary destination is overloaded. Another offering, referred to as "intelligent routing control" or "IRC" (from MCI), allows an ACD to refuse a call from the network, again resulting in pre-defined alternative call handling. A third kind of service, AT&T's Intelligent Call Processing, lets the interexchange network pass call-by-call data to a computer.
While these service offerings offer certain advantages over more conventional call routing, they have significant deficiencies. Such offerings do not provide for complex routing schemes based on comparative delay times, call center service level commitments or other similar considerations. These systems do not offer the user the opportunity in a straightforward way to create rules that define constraints and/or preferences for determining individual call routing. Many do not function effectively in case of data outages from one or more destinations. Such prior art systems are incapable of anticipating changes in staffing and redistributing load in anticipation of such changes. These systems are also prone to user errors and are difficult to use.
There has therefore been a long-felt need in the telephone call routing art to overcome these and other deficiencies of the prior art and to provide an efficient rules-based call routing scheme that can be implemented throughout the telephone network.